This disclosure concerns apparatuses and methods useful for sealing an opening in a body wall, such as an access opening in the wall of a blood vessel or a fistula. In particular, apparatus and methods are disclosed for closing and allowing healing of an opening in a tissue wall, whether made during a medical procedure (e.g. those in which apparatus or medicaments are introduced into tissue) or naturally occurring (e.g. as a result of malformation or disease).
It has long been known to insert devices into bodily vessels or conduits to provide therapy or for diagnostic purposes. For example, in cardiovascular medicine, it is known to insert catheters, stents and other devices into a patient's vascular system in order to evaluate or treat the patient. In the case of percutaneous transluminal angioplasty (PTA), an opening is made through the patient's skin and into a large or relatively large blood vessel, such as the femoral artery, and a balloon is inserted into the vessel and advanced to the location where vessel narrowing has occurred, such as by atherosclerosis. Similar procedures are used to implant stents to maintain flow through blood or other bodily vessels or ducts. In accessing the interior of a blood vessel, the interventionist or medical professional may breach the integrity of the vessel. A variety of devices (e.g. needles, guide wires, cannula) are known to open a path into a vessel via a percutaneous opening or other approach. Additional devices or implants can be moved through such devices, or through sleeves or cannula placed in the opening to keep it open, and into the vessel.
When the procedure is concluded, a cannula or other access device is removed from the vessel, leaving an opening in the vessel. If the arteriotomy is not adequately closed, a subcutaneous hematoma will form. The medical professional may therefore take steps to close the opening in the vessel. In some cases, the opening may be sutured closed, but such action can be very difficult in close quarters, and many vessel-accessing procedures are intended to be minimally-invasive to reduce tissue damage. It is also known to apply constant, firm external pressure to the opening in the vessel, particularly if it is a blood vessel, to allow the body's natural coagulation and healing processes to work. In cases in which angioplasty or similar treatment has taken place, however, commonly an anticoagulant has been administered to the patient, making natural closing of the opening in the vessel wall a longer or more difficult process. Maintaining physical pressure on a relatively large blood vessel for a time period sufficient for natural closure also presents at least inconvenience and discomfort to the patient in having to remain motionless and submit to that pressure, and there is the risk that too much pressure can damage the vessel or tissues that rely on continued flow through it.
Therapies for closing naturally-occurring fistulae or other undesirable bodily openings are also known. Treatments have included closure by suturing or by covering the opening, and by other surgical techniques. Frequently these therapies have required open surgeries with their attendant difficulties.
Devices have been created for inserting closures into a blood vessel or on its exterior that are designed to block the opening and/or soak up fluids that escape the vessel, or are present in the opening through the skin leading to the vessel. Such devices have, however, proven unsatisfactory in many respects, as have therapies for closing naturally-occurring openings in tissue. Needs therefore exist for improved and/or alternative devices and systems for inserting a closure for an opening in tissue that produces a seal without significantly blocking adjacent flow where desired (e.g. through a blood vessel), and fills the opening where that is desirable.